1. Field of the Invention
This invention relates to a wafer stage chamber design. More particularly, this invention relates to a wafer stage chamber assembly and method for making the wafer stage chamber assembly in a photolithography process to manufacture semiconductor wafers.
2. Description of the Related Art
In manufacturing integrated circuits using photolithography, light is transmitted through non-opaque portions of a pattern on a reticle, or photomask, through a projection exposure apparatus, and onto a wafer of specially-coated silicon or other semiconductor material. The uncovered portions of the coating, that are exposed to light, are cured. The uncured coating is then removed by an acid bath. Then, the layer of uncovered silicon is altered to produce one layer of the multi-layered integrated circuit. Conventional systems use visible and ultraviolet light for this process. Recently, however, visible and ultraviolet light have been replaced with electron, x-ray, and laser beams, which permit smaller and more intricate patterns.
As the miniaturization of a circuit pattern progresses, the focus depth of the projection exposure apparatus becomes very small, making it difficult to align accurately the overlay of circuit patterns of the multi-layered integrated circuit. As a result, a primary consideration for an overall design of the photolithography system includes building components of the system that achieve precision by maintaining small tolerances. Any vibration, distortion, or misalignment caused by internal, external or environmental disturbances must be kept at minimum. When these disturbances affect an individual part, the focusing properties of the photolithography system are collectively altered.
In a conventional exposure apparatus of a photolithography system, a wafer stage device is used in combination with a projection lens assembly to manufacture semiconductor wafers. The wafer stage device includes a wafer table to support the wafer substrates, a wafer stage to position the wafer substrates as the wafer stage is being accelerated by a force generated in response to a wafer manufacturing control system, and a wafer stage base to support the wafer stage. The wafer manufacturing control system is the central computerized control system executing the wafer manufacturing process. To permit smaller and more intricate circuit pattern, the projection lens assembly must accurately focus the energy beam to align the overlay of circuit patterns of the multi-layered integrated circuit. The photolithography process of the conventional exposure apparatus is performed with the semiconductor substrates exposed to the atmosphere.
Recent developments enabling the photolithography process to meet certain wafer manufacturing specifications and to improve the quality of the resulted wafers require that the semiconductor substrates be processed in a controlled atmosphere, such as nitrogen or helium. To take advantage of the recent developments, there is a need for a wafer stage chamber design to isolate the semiconductor substrates, the wafer stage device, and the manufacturing process thereof from the atmosphere.
The advantages and purposes of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages and purposes of the invention will be realized and attained by the elements and combinations particularly pointed out in the appended claims.
To attain the advantages and consistent with the principles of the invention, as embodied and broadly described herein, one aspect of the invention is a wafer stage chamber assembly for use in manufacturing semiconductor substrates, comprising a wafer stage chamber that seals a wafer stage device from the atmosphere outside the wafer stage chamber.
Another aspect of the present invention is a wafer stage chamber assembly for isolating a wafer stage device and used in a semiconductor wafer manufacturing system, comprising a chamber frame to enclose the wafer stage device, and a plurality of chamber walls including a front panel having at least one loader port for loading and unloading a plurality of semiconductor substrates into the wafer stage chamber.
A further aspect of the present invention is a method for making a wafer stage chamber assembly for use in manufacturing semiconductor substrates, comprising providing a wafer stage chamber for sealing a wafer stage device from the atmosphere, and providing at least one loader port for loading and unloading substrates into the wafer stage chamber.
Yet a further aspect of the present invention is a stage chamber assembly, comprising a stage chamber that seals at least one stage device from an external condition of a stage chamber, and at least one loader port connected to the stage chamber, the loader port allowing at least one of loading an object into the stage chamber and unloading the object out of the stage chamber.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed. Additional advantages will be set forth in the description which follows, and in part will be understood from the description, or may be learned by practice of the invention. The advantages and purposes may be obtained by means of the combinations set forth in the attached claims.